Today, the United Nations Intergovernmental Panel on Climate Change published an alarming report on climate change. It includes 14,000 pieces of scientific literature that were compiled by hundreds of experts. This is a comprehensive report that outlines what scientists know about the effects of human activity on the planet. It includes information such as how hot it has gotten, how hot it will get, the extent to which polar ice melts, the severity of droughts and storms, and the dire outlook for the future if we don't take immediate and drastic steps to reduce carbon emissions in the atmosphere.
We've known for decades that the world is warming, but this report tells us that recent changes in the climate are widespread, rapid, and intensifyingunprecedented in thousands of years, said Ko Barrett, IPCC vice chair and senior advisor for climate at the National Oceanic and Atmospheric Administration, at a press conference Sunday announcing the report. It is impossible to limit global warming below 1.5 degrees Cor 2.7 degrees Fahrenheit if there are not immediate, large-scale, rapid and significant reductions in greenhouse gas emission.
This limit is the optimistic goal set out in the Paris Climate Agreement. It aims to maintain global average temperatures at 1.5 degrees Celsius above preindustrial levels and to prevent 2 degrees of warming. According to the new report, the temperature has already risen by 1.1 degrees and will rise to 1.5 in the mid- to late-2030s if nothing changes.
This is a major update to an earlier IPCC report, which predicted the planet would reach the 1.5 milestone in 2040. Zeke Hausfather, a climate scientist, was not involved in the report. He also said that we are passing 2 degrees in the mid-2040s to early 2050s, which is the most likely estimate for higher-emission scenarios. This refers to one of five outcomes modelled in the new report.
What is the significance of a half degree? There is a significant difference between 1.5 and 2 in terms of the worsening droughts, heat waves and storms, ice melting, and sea level rising, according to Janos Pasztor (executive director of Carnegie Climate Governance Initiative) who was not involved in the report. It gets worse when you add two. Even worse, it gets worse if you go beyond 2. There are good chances that we will continue in this direction.
The report presents projections of what would happen under five different scenarios for greenhouse gas emissions. These scenario imagine an future where humanity produces varying amounts of carbon from very low levels to very high. (In the lowest scenario, the emissions fall to net zero by 2050 and continue falling. They double in the highest scenario. It predicts what the climate will look at depending on how fast our civilization decarbonizes.
These reports, which include color-coded graphics, also show what will happen to global temperatures, and precipitation rates, depending on how warm the climate gets. It also shows how many regions around the world have seen an increase in extreme heat, drought, and precipitation. (Hint, it's almost all of them.